1. Field of the Invention
This invention relates generally to improvements in fluid vapor injectors and, more particularly, but not by way of limitation, to an improved fluid vapor injector for injecting a fluid vapor into the intake manifold of an internal combustion engine.
2. Description of the Prior Art
The introduction of relatively small quantities of a fluid, such as water, in vapor form into the combustible fuel mixture utilized in an internal combustion engine generally results in slower and, therefore, more efficient burning of the fuel mixture within the combustion chamber of the engine. In general, the fluid vapor may be introduced into the intake portion of the engine via one of three methods. The first method utilizes a relatively low pressure within the intake portion of the engine to draw the fluid vapor into the carburetor or the intake manifold thereof, representative examples being shown in the U.S. Pat. Nos. 1,633,251 issued to Heinz and 1,497,533 issued to Barron. The second method utilizes exhaust manifold back pressure, sometimes in conjunction with the first method, to forcibly inject the fluid vapor into the carburetor or the intake manifold, representative examples being shown in the U.S. Pat. Nos. 2,445,479 issued to Francis and 2,493,808 issued to Garrigus. In the third method, a mechanical or electrical pump is utilized to forcibly inject the fluid vapor into the intake portion of the engine, an example being shown in the U.S. Pat. No. 2,392,565 issued to Anderson et al.
Control of the rate of introduction of the fluid vapor for various engine speeds has been generally accomplished using several methods and/or apparatus. In one method, a pressure-responsive valve is provided to vary the rate of injection in response to changes in intake manifold pressures, representative examples being shown in the U.S. Pat. Nos., 1,441,209 issued to Bollman, 1,613,789 issued to Devary and 1,623,053 issued to Howard et al. A more limited method utilizes pre-set or manually adjustable needle valves to vary the rate of injection of the fluid vapor into the intake portion of the engine, representative examples being shown in the U.S. Pat. Nos. 3,865,907 issued to Rock and 2,556,985 issued to Sparrow et al.
Related methods and apparatus are shown in the following U.S. Pat. Nos.: 1,918,898 issued to Covyeow; 2,300,774 issued to Cartmell; 2,551,836 issued to Gendreau; 2,556,986, issued to Sparrow et al; 2,591,272 issued to Littlejohn et al; 2,756,729 issued to Wolcott; 3,767,172 issued to Mills; 3,856,901 issued to Neumann et al; and 3,875,922 issued to Kirmss.